Gauge for grinding tool bits



April 2, 1946, L. H HOWE 2,397,738

GAUGE FOR GRINDING TOOL BITS Filed March 20, 1945 MEE 55 /NME/v TDR LH.Howe- /4 TTD/RNE 5/ Patented Apr. 2, v1946 UNITED STATES PATENT GFFICE 12,397,738 1 GAUGE Fon GRINDING 'rooL Brrs Louis H. Howe, Portland, Oreg.Application March 20, 1945, Serial No. 583,792

Claims.

This invention relates generally to the art of tool grinding. andparticularly to the grinding of bits for machine tools such as lathes,planers, Shapers, etc.

The main object of this invention is to provide a gauge which willobtain all faces of a bit without removing from gauge, and clampingmeans for more than one size without set screws and Wrenches. Y

The second object of this Vinyention is to provide an exceedingly simpleand eiflcient form of gauge for holding a tool bit during the grindingthereof whereby the side rake and side and end clearance angles may beestablished and maintained with the utmost precision by unskilledworkmen not especially trained in the tool grinding art.

'I'he third object is to construct al device of the class describedwhich will reduce the tendency for errors in the setting thereof andwhich will make it possible to grind the various faces of the bit 'witha single setting of the bit in `its holder.

The fourth object is to construct a device of the class described whichoperates `with equal success in grinding right or left handed bits.

The iifth object is to construct a holder of the class described inwhich there is provided an effective clamping action which will securelyhold bits of various sizes in place at all'times and which is providedwith an adapter whereby bits of square or rectangular cross section canbe ground with equal degree of satisfaction.

The sixth Objectis to so construct the device that any desiredangularity maybe obtained in order to t requirements for various typesof work and materials by means of interchangeable bases of differentangles and index hole positions and spacer washers of different tapers.

These and other objects are accomplished in the'manner set forth in thefollowing specification as illustrated in the accompanyingdrawing, inwhich:

Fig. 1 is a plan of the device.

Fig. 2 is a side elevation ofthe device showing same vin a position forgrinding'the side rake of a. bit. V

Fig. 3 is a side elevation showing the device in position for grindingthe side clearance on right hand bits.

Fig. 4 is a view similar to Fig. 1 showing the device set for grindingthe side clearance angle on a left hand bit, with parts broken away insection to disclose the inner mechanism.

Fig. 5 is a section taken along the line 5--5 in away from the normalFig. 3, showing the parts in position for ing side and end clearances.

Fig. 6 is a plan of the spacer washer. Fig. '7Y is a section taken alongthe line in Fig. 6. l

Fig. 8 is a plan of the base upon which the ldevice rests in theposition shown in Fig. 3.

Fig. 9 is a plan lof the foot upon which the device rests in Fig.2. I I

Fig. 10 is a transverse section through abit of rectangular crosssection showing my adapter therefor. I y

Similar numerals refer to similar parts throughout the several views. l

Referring in detail to the drawing, there is shown a body I4 having theiiat bottom 4face 'I5 and having a slot I6 formedtherethrough to receivea maximum width of bit I'I. intended .torbe held by the device. The sideI8 of theslot is normal to the bottom face I5. The side ;I9 of the slotis parellel to the side I8 and of much lesser height, and merges atits.y upper edge with the inclined face 20'which is inclined at an angleof 4:5l degrees with relation to the side I8.

The clamping jaw is mounted on a 45 degree grind:-

angle for the purpose of holding bits smaller than the maximum withouttheneed of adapters or set screws and wrenches. Quick change from rightto left feature is an advantage in grinding forming machine and materialbeing machined, resharpening is merely a matter of touching up asadjustments remain the same.

Mounted on the face 20 is a bit clamping arm 2I which is pivotal on thescrew 22` and is provided with an extension 23` having the clampingscrew 24 whose head v2liV is preferablyknurled.

The point l26 of the screw 24 rests upon the ledgev 21 formed near thebottom I5.V y y The sides 28.and 29 of the body I4 are inclined relationto the bottom I5. Underneath the bottom I5 is disposed a base 35i whichis in the form of a tapering washer whose under side 3l is intended torest upon thetable 32 of a grinder, the position of' whose.grindingvwheel 33 is indicated in the drawing toshow'its relationship to thedevice.

The top side 34 of the base 3B is provided with two holes 35 and 36adapted toregister with the pin 31 which is seated in the bottom I 5 ofthe body I4.

Since the base 30 is tapering it follows that the rotation of the base30 vwith relation to the body I4 will change its angularity from left toright as shown in Figs. 3 and 4, the purpose being to actools. Once thegauge is set for a i h'olding, the same against the face '92l hel'dwi'thmy device. an; adapter'A 54 whichY Y 4 Y 'aw whose side 55 is; thickerthan the side 5E; so

varying the end. clearance angle to meet a given requirement. The washer38 is provided' with one hole 39 only, since the taper of the washer 3Srepresents the amount of end clearance anger-LA larity which is added.

The base 30 is provided with a counter-bore 40 which receives the head4I of a: bottomilrg screw 42, which is threaded intdthe. body, I4. Aspring 43 is inserted between thescrew head 4I and the bottom of thecounter-bore 4&2 'l-'hey body I4 is provided with a recess 44 whichreceives a bossV 45' surroundingl the-'screw 4% and serves to center thebase iiwithrelation-V tof the body I4.,

The purpose of the spring 4'3 is to permit the l base 3,0 to be drawnaway from the body- I 4 sui'- ci'entl'y-*far to disengage the pin 3lfromk al hole l. A device of the class described consisting of a bodyhaving means for clamping a tool bit therein, a revolvable tapering basemounted under said body having means for holding same in one Vof twopositions, said body having opposite faces formed thereon inclined awayfrom a line normal to the bottom of said body, each of said faces havinga tapering foot revolvably mounted thereon, the taper on said foot andthe inclinationo its engaging base-.being equal, and means for indexingeach of said rfeet through one-half of its circumference whereby theouter face of a fo'ot may be vturned toga plane normal to the bottom. ofsaid body or away therefrom at an angle d'oubl'e the degree of taper ofsaid foot or in anyi-indexedintermediate position. 2. A device of. theclass described consisting of a bodyhavinga tapering base revolvablymounted Ori-.under side thereof, including means for limiting therelative positions thereof to one or the other of opposite positions,mear-1s Vfor clam-ping a tool bit acrossl said bod-5rl in inclinedrelation to thebottom thereof'between its tapering or Stand permit therelative rotation ofjthe membersY f4 and 30 for right and left hand sideclearance grinding.

In Fig; 2 it will be noted that' the device is turned' over on its side.Tha-t is, aface 29- rests upon the calibrated tapering side-raker foot;46

having a screw 4'I and spring 48 for yield-ably The foot 46 is'providedwith-a central opening 4! for'thescrew 41 andthe counter-bore50VIV for the head of the screw- GT. The root 46 is also providedY withan arcuatey row ofiv index holest adapted to engage; the index' pin 52w'h-ichfv is mountedv on the body I4 and projects from; the

face 29.# Y

It can be seen that irr this position, the 'side rake can lbe obtainedand maintained withy the utmostaccuracy and no resetting ofi thebit isrequiredfor grindingthe variousfaces.

In Fig: 10 there is shfown a bit53 of rectangular cross section.Itrollows that since' the angleof n the face 2U with relation to thefaceV I8L is 45 degrees that such a bit could notl be satisfactorily lVYhave therefore provided is' in the form oran angle that the corner 5'Iwill'lie in a diagonali-'inermning'throughthe corner 58 of the bit 53..It is,

device` described hereinV is anim..

" clamping screw disposed' thereon adapted toen'- gagesaid body andcause the opposite end 'orsaid clamping jaw to engage a tool bitdisposed within said slot, and' to exert a pressure against samediagonally'across opposite cornersoffsaid'bit 4i. A clamp for a tool bitholder consisting of 1a body having av slot thereinfor the reception ofa square bit, one side of vsai 'd` slot being inclined alongA a. planeparallel toy 1aY planewhcliintersects thediagonally'opposite corner of1saidfbita elamp-A ing ia-w pivotally mounted: onv sai-di inclined-'-face having' one. endV notched to engage a corn-fer of saidf bit. and:the opposite end 'provided' with 'a'V clamping screw, the end ofsaid'clamping screw engaging' said body whereby: the; tightening of saidscrew against; said bcdywiill endorsaidclamptobear again-st said bit;

5. A holder forv gnindingtbol'bi'ts consisting or a body having a flatunderside,y .and having an inclined slot formed across-same'. frorntheupper side,y one side of said slot being: norma-l to: Vthe pla-ne of theunderside of said body'andthe other side of said slot: beinginclined'ina, plane45fdegrecs. from the normal side'of said slot', a clamping jawpivotally mounted on the inclineds'ide ofy said.- slot having aA notchtherein adaptedfto Swingin a plane intersectingI the iunctionof saidnormal side and slot bottom, thei endet said clamping jawoppositejitsgroovedend having' a clamping,` screw mounted,thereonfadapted toeensaee theA lower portionor said bed-y member..

LOUIS H. HOWE.;

causefthenotched

